System for supplying power to consumers

ABSTRACT

An arrangement for supplying mobile consumers which have an on-board power generation system, and a fuel tank for storing a fuel for operating the power generation system, includes a stationary discharge device for transferring fuel from a stationary fuel source to the fuel tank. The discharge device includes a supply unit for supplying fuel to the consumer, and the consumer has corresponding holding unit with a tank connection for holding fuel. The discharge device also has electricity consuming devices, and the holding means is also equipped with a corresponding means for electricity emission.

BACKGROUND AND SUMMARY OF THE INVENTION

[0001] This application claims the priority of German patent document 101 29 096.9, filed Jun. 16, 2002, the disclosure of which is expressly incorporated by reference herein.

[0002] The invention relates to an arrangement for supplying energy to and from mobile power consuming devices.

[0003] Widespread use of fuel cell vehicles is dependent on adequate fuel accessibility, including broadening of the necessary infrastructure for delivery of fuel. For methanol-powered fuel cell vehicles, conversion measures may be required at refueling stations, in order to make it possible to offer methanol; and for hydrogen-powered fuel cell vehicles, an adequate hydrogen infrastructure is required, which is also conveniently accessible for private operators of fuel cell vehicles.

[0004] Because the provision of such an adequate infrastructure for supplying fuel cell vehicles is costly and time-consuming, the accessibility of an appropriately equipped refueling station for fuel cell vehicles may not be ensured. Furthermore, during a transitional period in which large numbers of conventionally powered vehicles still need to be supplied, it will be necessary for refueling stations to keep large stocks of widely different fuels. This requirement will make it more difficult for, and increases the costs associated with, large-scale introduction of fuel-cell powered vehicles.

[0005] U.S. Pat. No. 6,065,511 A1 discloses a vehicle refueling system in which, for example, commercial vehicles can be refueled by means of a tanker vehicle, in much the same way that aircraft are refueled by tanker aircraft in the air. For this purpose, vehicles are positioned in a predetermined parking area. At the same time, a tanker vehicle is requested for this area, and payment for the refueling is initiated. The vehicle can be refueled while the driver has left the vehicle and is engaged in other activities. Vehicle servicing is likewise possible. On leaving the area, the driver is provided with a statement of the amount of fuel added, and the cost of refueling.

[0006] One object of the present invention is to provide an improved arrangement for making a decentralized power supply available to consumers, particularly vehicles.

[0007] This and other objects and advantages are achieved by the method and apparatus according to the invention, which eliminates the need for costly conversion measures or investments for existing refueling stations, because existing stationary systems can be used for refueling mobile consumers; and in addition, electrical power can be fed back from a fuel-cell vehicle into stationary systems when the vehicle is at rest, so that any stationary consumption peaks can be covered by decentralized feedback from vehicles that produce power. The refueling options according to the invention are so widely available that they are easily accessible.

[0008] Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009]FIG. 1 is a schematic view of a preferred arrangement according to the invention, with a fuel-cell vehicle and a fuel source;

[0010]FIG. 2 shows a preferred discharge means with corresponding connecting means on the vehicle side; and

[0011]FIG. 3 shows an arrangement of fuel-cell-powered vehicles.

DETAILED DESCRIPTION OF THE INVENTION

[0012] The invention is particularly suitable for fuel cell systems which are supplied with alcohols, hydrocarbons, ether, esters or hydrogen, but it is not restricted to these fuels.

[0013] Fuel cell systems are attractive and compact power supply systems that are highly suitable for stationary consumers, including both large consumers such as power stations, and small consumers such as private households or businesses, which are supplied with electrical power from fuel cell systems. These systems require a fuel supply, in the form of reservoir tanks for a suitable agent or a cable network with sufficient capacity to transport a suitable fuel to the stationary consumers.

[0014]FIG. 1 shows a preferred embodiment of the invention, in which a fuel tank 2 of a mobile consumer 1 with a fuel cell system 4 is supplied from a stationary fuel source 5, which also supplies a stationary consumer 6 with a fuel 3 for heat and/or electrical power. The stationary consumer 6, preferably a building, is supplied in a particularly advantageous manner with fuel 3 for operation of a stationary fuel cell system, which in turn supplies electrical loads in the building 6.

[0015] The fuel source 5 may, for example, be a storage tank, in which a fuel 3 is stored, to be reformed to obtain hydrogen; such fuel may be, for example, alcohols such as methanol or ethanol and hydrocarbons such as natural gas or petrol, ethers such as dimethyl ether, esters or other suitable compounds containing hydrogen. The vehicle 1 accepts the fuel and reforms it in an on-board gas generation unit 4 a, to hydrogen to provide hydrogen for a fuel cell unit in the on-board fuel cell system 4.

[0016] The fuel source 5 may also be a hydrogen tank in which hydrogen is stored in a stationary form as a fuel 3, with there being no need for on-board reformation. Alternatively, the fuel source 5 may include a stationary reformation unit, by which means fuel which is available from a stationary source is first of all reformed, and the tank 2 of the vehicle 1 can then be filled with the fuel 3 in the form of hydrogen-rich reformate. In this case, reformate cleaning can also be provided in stationary form, or can be carried out on board the vehicle 1.

[0017] However, the fuel 3 may also be supplied to a conventional power supply for the stationary consumer 6, such as natural gas or mineral oil for a conventional heat and hot-water supply, via a heating boiler supplied by the fuel source 5.

[0018] The stationary fuel source 5 has an associated means 9 which may include, for example a filling nozzle, for discharging fuel 3 and transferring it into the on-board tank 2. The discharge means 9 has an associated recording unit 11, which records the discharge of the fuel 3 and allows a form of payment, such as a card reader for cash cards, customer cards or credit cards. The advantage of this arrangement is that fuel cell vehicles can be supplied with fuel in a decentralized manner.

[0019] Fuel cell systems are now becoming attractive as compact power supply systems that are also highly suitable for stationary consumers 6, including large consumers such as power stations as well as small consumers such as private households or businesses that are supplied with electrical power from fuel cell systems. These necessarily require a supply, preferably reservoir tanks for a suitable fuel 3.

[0020] The stationary consumers themselves are arranged in a decentralized manner, for example in residential areas, industrial areas or mixed residential and commercial areas. According to the invention, the infrastructure provided there may also be used in a particularly advantageous manner for supplying mobile consumers. For example, a private household whose stationary power supply is provided by fuel cells can easily refuel a fuel cell vehicle or can supply the neighborhood with fuel 3 for their fuel cell vehicles. This ensures that a reliable infrastructure is set up and made available for decentralized supply of fuel 3 to mobile consumers 1, without need of complex conversion or modification of conventional refueling stations for gasoline or diesel.

[0021] It is particularly advantageous for the discharge means 9 to be provided with an input in order to feed electrical power from a mobile consumer 1 into the stationary system of the consumer 6; in this case the consumer 6 may also be a communal power supply network or a power supply network for a commercial power supplier. The electrical connection for feeding in the power may in this case be conductive via an electrical connection, or non-contacting (inductive).

[0022] For this purpose, the recording unit 11 can be equipped with a meter which measures the amount of electrical power fed in and, for example, produces a credit note. An invoice can advantageously be produced for the fuel 3 drawn against the electrical power fed in (“fuel for electricity”). It is particularly advantageous for the vehicle 1 also to be equipped with a conventional milometer with an operating hours counter, which records the amount of electrical power fed to a stationary consumer 6, and invoices this by means of a credit note, discount or the like. In this case, a credit account can be maintained for the mobile electricity-generating consumer 1 allowing, for example, the mobile consumer 1 to be refueled at low cost or as a debit against the credit account, while travelling. This can expediently be matched by means of the operating hours counter. Such an input feed can in principle also be produced by other vehicles, for example hybrid vehicles with an electrical drive motor.

[0023] It is advantageous to provide storage means and/or identification means at an electrical power feed point (preferably for example at a discharge means 9 and/or in the vehicle 1), which can associate a respective user with the fuel 3 drawn from a stationary discharge means 9 and the electrical power fed in from the mobile consumer 1, and can balance these against one another in a suitable way. This refinement thus allows, for example, a fuel account for travelling or for any stationary personal requirement for the owner of the vehicle 1 himself.

[0024] In a particularly advantageous manner, parked vehicles 1 can generate electricity for stationary consumers 6, for example from a parking space, when these vehicles 1 are connected to the stationary fuel source 5. In a refinement such as this, the power drawn by the stationary systems from this connection may turn out to be less than if they had to be supplied with electricity autonomously. This is particularly advantageous, for example, for shopping centers, businesses with company parking spaces or other such consumers, which are continuously used by visitors, who are preferably arriving with vehicles 1. The particular stationary power connection would then need to cover only a basic load, since power peaks can be covered by feeding in electrical power from visitors' vehicles. In this case, it is advantageous that the power requirement of such centers is considerably higher during business hours than during non-working hours, so that a large number of vehicles 1 are also available at times when the need for power is higher.

[0025] In one preferred further refinement of the invention, the discharge means 9 includes an associated control system which measures the electricity requirement of the stationary consumer 6 and emits a corresponding power request to a parked vehicle 1 or a number of vehicles 1. The respective on-board fuel cell system 4 emits appropriate electrical power, while the on-board tank 2 is expediently filled from the fuel source 5 at the same time.

[0026] If another vehicle 1 arrives, or drives away, the amount of electrical power currently available and the requirement for electrical power will be redetermined and stabilized once again. Fluctuations in the electricity requirement of the stationary consumer 6 can be distributed between a number of such vehicles 1, in order to smooth out the dynamic load. One or more vehicles 1 may optionally be operated purely dynamically, while all the other vehicles 1 which are connected to the control system and to the fuel source 5 are kept at an advantageous operating point, in order to minimize the control complexity. An electric meter is expediently provided in the vehicles 1 and is coupled to the discharge means 9, so that the fuel 3 consumed can be automatically replenished. The electric meter may also, however, be installed in stationary form. Furthermore, the control system may also include a computer, which stores a credit for the mobile consumer 1 which is feeding electricity into the system, with this possibly being updated by balancing it against fuel drawn from a discharge means 9.

[0027] In this case, in order to compensate for the operating costs and as an incentive for vehicle owners, it may be advantageous to provide more fuel 3 than is consumed for the stationary feeding-in of electricity, or for the building operator to provide a fuel credit note or to make a payment to the vehicle keeper in the form of cash, or to store it for him. A device which allows electricity to be exchanged for fuel supra-regionally as well, is particularly advantageous.

[0028] As depicted schematically in FIG. 2, one preferred discharge means 9 has a plug connection which allows a vehicle 1 easily to be connected to and disconnected from the discharge means 9 and the fuel source 5 without major installation effort. The plug connection comprises an electricity supply 12 for feeding in electrical power from the vehicle 1 to the stationary consumer 6 and/or for feeding it into a power supply network, a fuel supply line 13 for transferring the fuel 3 from the fuel source 5 into the tank 2, optionally an exhaust gas line 14 for sucking out fuel 3 which emerges during the refueling process and, preferably, an identification means 15 for the vehicle 1 and/or for the discharge means 9.

[0029] In a corresponding way, the vehicle 1 has connecting means 16 for fuel discharge and feeding in electricity, namely an electricity output 17 for feeding electrical power from the vehicle 1 to the stationary consumer 6 or into a power supply network, a tank opening 18, which matches the fuel supply line, for transferring the fuel from the fuel source 5 into the tank 2, and, expediently, an identification means 19 for the vehicle 1 and/or for the discharge means 9. The electrical means 12, 17 and the fuel connections 13, 18 may also be physically separate from one another, in order to reduce the risk of spark formation. The discharge means 9 may expediently have associated recording means 11. It is advantageous, in addition to suction for emerging fuel, to provide suction for emerging exhaust gases. This is particularly expedient in multistorey car parks or other locations where the requirements for a clean and/or safe environment are particularly stringent.

[0030] One particular advantage of an arrangement such as this is that the on-board fuel cell system 4 may also be active and at its operating temperature when in the parked state, thus avoiding the cold starting problems, particularly at low ambient temperatures, for example after a long working day. There is no need for cold starting, and the vehicle is in fact ready to be used immediately.

[0031] Particularly in the case of vehicle fleets, such as city buses or haulage companies, vehicles which are currently not in use, during breaks and at night, can be connected to the regional electricity network in order to cover the peak domestic demand for electrical power. The exceedingly good dynamics of vehicles 1 with on-board fuel cell systems 4 and the mutual reduction in the loads on a relatively large number of vehicle-based electricity feeders make it possible to increase the overall electric generation efficiency, and to create redundancy. Better availability is provided by there being a number of mutually independent systems. For example, vehicle-based electricity feeding from commercial vehicles which are stopped at a service station where they feed electrical power from the on-board fuel cell system 4 into stationary systems, is particularly advantageous. This would allow virtually 100% utilization by a haulage company since, when the vehicles are stationary, they are providing electrical power (thus, producing profit), even though they are not being driven.

[0032] The vehicle-side connecting means 17 can particularly advantageously be used as a starting aid or for “assisted towing” of a broken-down vehicle 1′. This is shown in FIG. 3. When the electrical contacts 17, 17′ of an assisting vehicle 1 and of a broken-down vehicle 1′ are connected, for example with the aid of an appropriate adapter 20, the on-board fuel cell system 4 of the assisting vehicle 1 can provide the broken-down vehicle 1′ with electrical power for starting its system, for example for compressor power, metering pumps, electrical heating and the like. The electricity emission connection 17, 17′ then, overall, becomes a starter cable for fuel cell systems.

[0033] For assisting towing of a broken-down vehicle 1′ with a damaged fuel cell system 4′, the damaged fuel cell system 4′ can thus be bridged, with the fuel cell system 4 of the towing vehicle 1 supplying the electrical drive of the broken-down vehicle 1′. The conventional towing cable or towbar is replaced by a towing cable which can also electronically transmit braking pulses to the vehicle 1′ that is being towed.

[0034] The solution according to the invention could supplement and replace the previous refueling station infrastructure, particularly when decentralized, stationary power supply units based on fuel cells are used. These units can be provided for relatively large buildings, such as apartment blocks, commercial buildings etc., as well as for individual houses. These units 6 must also be supplied with a fuel 3 for operation. Individual houses can be supplied using tanker vehicles. For larger units, direct supply via a pipeline network, such as a natural gas supply, is feasible. The invention allows the use of a supply network which is already in existence and is fully configured for stationary consumers, even for supplying fuel 3 to mobile consumers 1 with fuel cell systems.

[0035] The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof. 

What is claimed is:
 1. A system for supplying mobile energy consumers which have a power generation device and a fuel tank for storing at least one fuel for operating the power generation device, said system comprising: a stationary discharge means for transferring fuel from a stationary fuel source to the fuel tank; supply means included in the discharge means, for supplying fuel to the consumer; and corresponding connecting means provided at the consumer, said connecting means having a tank connection for receiving fuel; wherein the discharge means includes electricity consuming devices; and the connecting means is also equipped with a corresponding means for electricity emission.
 2. The system according to claim 1, wherein: the discharge means includes associated recording means for recording an amount of fuel discharged.
 3. The system according to claim 1, wherein at least one of the discharge means and the holding means includes identification means for identifying at least one of the discharge means, the fuel source and the mobile consumer.
 4. The system according to claim 1, wherein the discharge means also has a fuel suction device.
 5. The system according to claim 1, wherein the discharge means also has an exhaust gas suction device.
 6. The system according to claim 1, wherein at least one of the recording means, the discharge means and the holding means is connected to a control system which detects, controls, or detects and controls an electricity requirement of a stationary consumer and the availability of electrical power by mobile consumers.
 7. The system according to claim 1, wherein the mobile consumer includes a counter which records at least one of emitted electrical power and any consumed amount of fuel.
 8. The system according to claim 1, wherein the fuel source stores fuel for supplying heat or electricity to a stationary consumer.
 9. The system according to claim 1, wherein a corresponding connection piece is provided for connection between electricity interfaces of two mobile consumers.
 10. The system according to claim 9, wherein when two mobile consumers are connected together, a braking signal can be transmitted via the connecting means.
 11. A power supply system, comprising: a mobile unit having an on board power generation device and a fuel tank which holds fuel for operating the on board power generation device; a stationary unit having a fuel source for supplying fuel to said fuel tank of said mobile unit, and also having an electric power output for supplying electric power to at least one of a communal power supply network and a stationary electric consuming installation; and a coupling element for detachable coupling said stationary unit to said mobile unit, said coupling element including a path for providing fuel from the fuel source to the fuel tank of the mobile unit and a path for supplying electric power generated by said on board power generation unit, via said stationary unit, to said at least one of a communal power supply network and a stationary electric consuming installation.
 12. The power supply system according to claim 11, further comprising: means for measuring and storing a value indicative of an amount of fuel supplied to said mobile unit from said stationary unit, and a value indicative of an amount of electrical energy supplied from said mobile unit to said stationary unit. 